Hi
Problem isn't yet resolved.

The following code is relevant
.open > .dropdown-menu {
display: block;
}

When the button is clicked the .open class should appear in the html so that the dropdown menu can be displayed.
Clicking the button does not toggle the menu. To get the menu to display you need to click the button and then hover over the little arrow and then the open class appears in the html . To toggle the dropdown menu off you have to click outside of the button. .
i.e.
<div class="nav-hover">
<div class="btn-group open">
<a class="btn btn-default" data-toggle="dropdown" aria-expanded="false"> ....

It works correctly with the Protostar template

Hope you have some ideas,
Regards

The problem still exists.

I have tested other joomla templates with the other Kunena templates and the buttons work correctly.

It seems there is an incompatibility with the sj_vicmagz and the Kunena forum.
Is it possible for you to test the operation of this template with Kunena and provide a solution for the correct operation of the bootstrap dropdown buttons (split).

The error can be seen when logged in to flylife.com.au forum and select a topic from the Forum Latest module on the right. All split buttons with the dropdown icon (i.e. Action) do not toggle correctly.
Regards